Providing expansion or enlargement to blood vessels and other tubular organs of the body including coronary arteries and veins, peripheral arteries and veins, the aorta, the aortic root, and the left ventricular outflow tract is often accomplished with a balloon catheter or other dilating catheter having an expansion balloon or other expanding member that places the expanding member into contact with the tubular member of the body. Often an expanding member is a dilatation balloon that is introduced in a smaller diameter configuration and is expanded in situ to cause a narrow portion in the tubular member to become enlarged in diameter. This angioplasty or vessel reforming procedure is accomplished to enlarge the stenosis found in coronary, peripheral, or other vessels of the body and thereby provide a larger lumen for blood or fluid flow and improve perfusion or fluid delivery to the tissue being supplied by the vessel. In a similar manner valvuloplasty is performed using a catheter with a balloon near its distal end to expand the diseased and stenotic aortic valve leaflets or other valve leaflets of the heart in order to allow improve blood flow through a specific valve or as a predilitation before the implantation of a percutaneously implanted valve. The catheter is generally introduced through the femoral artery and is advanced in a small diameter configuration across the aortic valve leaflets such that a portion of the balloon resides within the aortic sinus and a portion also can reside in the left ventricular outflow tract. The balloon is inflated into contact with the leaflets and thereby push or expand the leaflets outward into contact with the wall of the aortic sinus region. Such extension of the aortic valve leaflets allows the valve to open to provide a greater flow area. Alternately, in the case of predilitation prior to trans-catheter aortic valve implantation (TAVI), the aortic valve leaflets have been properly conditioned or expanded to receive the trans-catheter implant of a stented aortic valve. Other vessels of the body that could be dilated include the lymphatic vessels, esophagus, trachea, the intestinal tract, bile ducts, the urinary tract, or other tubular members of the body.
During the angioplasty or valvuloplasty procedure using a balloon dilatation catheter, blood flow across the inflated balloon is blocked thereby preventing the normal flow of blood through the tubular member of the body. For the case of coronary angioplasty, blood flow to the distal coronary tissue bed can be temporarily halted during balloon inflation resulting in lack of proper oxygen delivery to the myocardium. The myocardium can only survive for a period of several minutes without oxygen before tissue damage can occur. For the case of aortic valvuloplasty, blood flow from the left ventricle of the heart is temporarily blocked by the inflated balloon resulting in a reduced oxygen delivery to the brain, the heart, and other tissues of the body. The brain cannot function adequately if it is deprived of blood-carrying oxygen for period of only 15-30 seconds. Therefore, during such valvuloplasty procedures, balloon inflation must be maintained for only a short period of time.
It is the purpose of the present invention to provide an interventional catheter with a valvuloplasty balloon that will allow perfusion of blood to occur while the balloon is inflated to dilate the valve leaflets. A similar but smaller diameter device could be used to provide perfusion to the coronary arteries. A similar but proportionately sized interventional perfusion balloon catheter could be used to allow perfusion to any tubular member of the body while the balloon is inflated. Alternately, the distal expanding member of the device need not be a balloon, but could be expanded via mechanical means. The present invention allows a small diameter catheter to be inserted either percutaneously or via trans-catheter access across a stenotic or narrowed region of a tubular body member. As the expandable member is enlarged to dilate a stenotic region, perfusion of body fluid through the tubular member of the body is maintained.